Raleigh Twenty Rebuild
8th Nov 2008, 21:40:17
I needed to find a bike with a step-through frame, low bottom bracket and short cranks so that my mother (with a knee injury) could get back on a bike. There's almost nothing being made today that fits the bill. I bought a battered Raleigh Twenty and set about rebuilding it.
Here it is in all its original snot green glory. The chromed steel wheel rims had completely corroded through, the tyres were perished, almost every moving part needed replacing, but the frame and forks were sound. I set about stripping everything down so that the frame could be re-painted.
The Raleigh Twenty was named because of its 20" wheels, which were actually 451mm. There are still some 451mm wheels available, but only in steel. Switching to 406mm wheels used on BMX bikes allowed me to use double walled alloy rims which are much lighter and give better braking. I laced up some Sun CR18 rims to the original hubs. Sheldon Brown's site had links which allowed me to calculate the spoke lengths required. SJS Cycles have lots of products for small-wheeled bikes, I really recommend them. It was pretty easy to actually build the wheels, using the directions on Sheldon's site.
The finished wheelbuild. I fitted Schwalbe Marathons because of their excellent puncture resistance and cushiony ride. Thankfully, the original brakes fitted to this Twenty have a really long reach and were able to handle the 22.5mm difference between between the 406 wheels and the originals. However, It was necessary to file the hole in the rear brake bridge into a slot to get an additional 5mm or so drop for the rear wheel.
Here's the frame after I got it back from the powder coater. I took it to Faircharm Restorations in Leicester who did a really nice job on it. I made my own headset press from a length of threaded rod and some plate washers to get the headset cup back in the head tube before taking this photo.
This is the finished product. The bike rides really well considering it was made in 1977. The smaller wheels have actually lowered the bottom bracket even more and this does make for very poor clearance between the pedals and the ground, but cornering is fine if the cranks are kept horizontal. The Sturmey Archer AW three speed hub is a bit clunky compared to more modern designs, there is a 'neutral' gear between 1st and 2nd which is a bit disconcerting. A ladies' saddle, alloy seatpost, a Carradice saddlebag and some replacement handlebar grips complete the build.
Thankfully, after all the work I put into it, my mum is thrilled with the bike. The geometry of this bike really suits anyone with restricted movement in the knees. I've found that it's fun to ride as a runabout even if your knees are fine.
1 Archived Comment
31st Oct 2009, 20:42:34 by bikester
First class restoration. I really like to see these old bikes brought back to life in this throw-away world. I just bought an old Raleigh Nova for £10, in very nice condition. There's a bit of a judder in the headset though when braking at speed. I find this a real nuisance and am thinking of threading the forks down to fit an upper headset race instead of the nylon bushing. I can't understand why Raleigh made all their SWs like this. Love the colour of your respray.